The field of tissue engineering has resulted in the development of biocompatible scaffolds with significant potential for use in the repair and regeneration of tissue. For example, the use of porous mesh plugs composed of hydroxy acid polymers such as polylactide for healing bone voids was described by Brekke (see U.S. Pat. No. 4,186,448). Open cell tantalum structures are described by Kaplan (see U.S. Pat. No. 5,282,861). Biodegradable and bioresorbable templates are created using leachables as described by Mikos (see U.S. Pat. Nos. 5,522,895 and 5,514,378). Multi-phase bioerodible implants and methods have been described by Athanasiou (see U.S. Pat. No. 5,607,474). Scaffolds can also be produced using vacuum foaming techniques as described by Brekke (see U.S. Pat. Nos. 5,755,792 and 5,133,755). Molded porous biodegradable polymer implants can also be created as described by Walter (see U.S. Pat. No. 5,716,413). A biodegradable foam useful for cell transplantation is described by Leong (see U.S. Pat. No. 5,686,091). A polymeric foam with continuous open cell pores containing living cells is described by Shalaby (see U.S. Pat. No. 5,677,355). The preparation of a three-dimensional fibrous scaffold for attaching cells to produce vascularized tissue in vivo is described by Vacanti (see U.S. Pat. No. 5,770,193). Textile based porous scaffolds have also been described (see U.S. Pat. Nos. 5,770,193 and 5,711,960). A hernia mesh with two or more functional components or layers with different degradation rates is described by Tormala (see U.S. Pat. No. 6,319,264). Microfabricated membranes and matrices with a three-dimensional topography are described by Morgan (see U.S. Pat. No. 6,479,072). Foam based scaffolds have also been described by Vyakarnam (see EP 1452191A2 and EP 1064958B1). Two layered structures based on cultured cells are described by Murphy (see EP 1131410B1).